Icma 776 – Pre-setting angle valve with thermostatic option

Thermostatic valves are used to regulate and cut-off the flow of the heat transfer fluid that circulates inside air-conditioning
system terminals (radiators, fan coils, etc.).
Thermostat control devices are used in combination with the thermostatic valves to automatically regulate ambient
temperature wherever they are installed, keeping the temperature at a preset value. This avoids the needless wasting of heat
and provides a considerable saving of energy.

ICMA thermostat control devices can be installed on all thermostatic valves of this line to convert heating systems with
manual operating mode to automatic operating mode.
To install the thermostat control device, simply replace the thermostatic valve knob with an ICMA thermostat control
device. This is done with a few easy operations. These are described in detail in the paragraph “Thermostat Control
Device Installation and Regulation”.
The valves come in “straight” and “angled” versions so that they can be connected to two different types of pipes, at the
side of the heating system:
− The valves with GAS thread (side of heating system) are designed for connection to a steel pipe.
− The valves with standard ICMA thread (side of heating system) are designed for connection to a copper pipe, a
polyethylene pipe and a multi-layer polyethylene pipe, for which specific pipe fittings are provided.
Pressure loss can be detected by following the indications provided in the diagrams shown in the paragraph “Fluid
Dynamic Characteristics”.

Install ICMA thermostatic valves on the heating system making sure to observe the direction of flow. The fluid must
enter from the side on which the valve is connected to the system and go out toward the heating body.
The following problems can occur if the valve is installed incorrectly:
– A noise similar to a continuous sound of heavy hammering is due to the passage of fluid through the valve in the
wrong direction. This problem can only be solved by inverting the valve with holder on radiators that have this
problem, thus restoring the correct direction of flow of the fluid inside the valve.
– A noise similar to a sound of heavy whistling during the succession of specified on and off times is due to an excessive flow
inside the valve. This problem can be solved by keeping the system pressure under control, and equipping the system with
variable rotation pumps along with differential pressure regulators, or by making use of differential by-pass valves.

Double adjustment thermostatic valves have a
double regulation system that allow to limit the
maximum flow of valves in fully open condition.
This regulation doesn’t affect or modify the
standard functioning of valves during work both
“manual” either “automatic.
The “double adjustment” is set at the factory during
the final testing of the valves at the maximum flow
rate, it is advisable not to modify it unless specific
requirements are met.
The choice of the valve model and its dimensions
must be in accordance with the plant requirements
and the required hydraulic characteristics such as:
flow rate and leakage.

As mentioned above, the “double regulation” system allows limiting the
maximum flow rate of a valve to the complete opening condition, which
simplifies the balancing of a plant or the setting of the Kv of each single valve.
To change the “double adjustment” you need to do the following:
1) Remove the cap or thermostatic head on the thermostatic valve (the valve
will show as in fig. A).
2) Rotate the appropriate actuating rod (fig. B), matching the number shown
with the reference on the valve body using a key (Fig. C)
– The numbers 1 to 5 on the operating rod indicate the 5 different fluid flow
resistors
In the section “Fluid dynamics” at the bottom of this data sheet, there are
diagrams of the load losses related to the different valve models and their
measurements.
The numbered curves on the diagrams correspond to the number on the
maneuvering rod and consequently to the degree of valve adjustment:

The thermostat head is made of a series of plastic parts containing a
thermostatic component that is sensitive to temperature variations.
Operation of the thermostatic component is based on the expansion of the
thermostatic liquid contained inside it:
− when the ambient temperature rises, the thermostatic liquid increases in
volume, resulting in the lengthening of the component;
− when the ambient temperature drops, the thermostatic liquid decreases in
volume, resulting in the shortening of the component.
The variations in length of the thermostatic component are transmitted to
the valve obturator by a small steel rod. These movements constantly
regulate the flow of the heat transfer fluid to the heating component so that
the temperature set on the thermostat control device remains constant over
time.
The thermostat control device components are specially made of plastic
materials to prevent the valve heat and that irradiated by the heating
component from being transmitted to the thermostatic component by
contact or induction. This prevents possible malfunctions in the control
device.
The thermostat control device temperature is regulated by turning the
numbered knob and bringing the corresponding symbol to the desired
temperature close to the head indicator (see the following paragraph for
more details).
– Position 3 on the adjustment scale corresponds to an ambient temperature
of 20°C. This is the recommended temperature for ensuring a comfortable
environment and reduced heat consumption and costs.
− The asterisk “*” indicates the freezing protection position. When the
thermostat control device is set to this position, the valve turns on only if
the ambient temperature drops below 6°C.
This setting is recommended when one is absent for long period of time
during the winter months, or when one wishes to aerate the premises
when outside temperatures are very low.

Fluids used: Water and glycol solutions
Maximum percentage of glycol: 50%
Maximum operating pressure: 10 Bar
Maximum differential pressure: 1 Bar (with control device mounted)
Temperature of heat transfer fluid: 5 to 120°C
Valve obturator travel: 3.5 mm
Connection with thermostat control devices: M30x1.5
Pre-setting condition: Position 5
Materials
Body, cap and socket union: CW617N Brass – UNI 12165 – Nickel-plated
Large screw: CW617N Brass – UNI 12164
Spring and obturator control rod: Stainless steel
Liquid sealings: Peroxy EPDM
Control knob: Nylon 6 – 30% Fibreglass (White

Minimum adjustment calibration (anti-freeze position): ts min 7°C (*)
Maximum adjustment calibration (position): ts max 28°C (5)
Saving condition (position): 20°C (3)
Maximum working pressure: PN 1000 KPa
Maximum differential pressure: Δp 100 KPa
Nominal capacity “qm N” (DP=10 KPa) angle-straight: qm N 191 to 195 Kg/h
Maximum working temperature: 110°C
Maximum storage temperature: 50°C
Hysteresis: C 0.25 K
Authority: a 0.9
Response time: Z 27 min
Differential pressure influence: D 0,55 K
Water temperature influence: W 0,6 K
Connection to thermostatic expansion valves: M30x1.5

Thermostat control device conform with Standard: EN215
The thermostatic valve is fitted with manual adjustment handwheel (rotation)

Materials
Knob and stop ring: RAL 9010 ABS White
Body and transmitter: RAL 9010 PA6 30% F.V.
Sensor liquid: Thermostatic ethyl-acetate
Connection ring: CW617N Brass – UNI 12164 – Nickel-plated
Compensation pin: CW617N Brass – UNI 12164
Compensation pin spring: SH steel for springs – Phosphated